ARCHIVED ADVISORY - All advisories expire after 24 hours from the posting date/time.

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The Bottom Line

The hazard will ratchet up to CONSIDERABLE today above treeline, especially this afternoon. The hazard below treeline will also rise from MODERATE to CONSIDERABLE later today. Rapid loading of new windlblown snow alone will make for dangerous avalanche conditions. Natural avalanches are possible and human triggered avalanches will be likely at all elevations today. The general trend for the day is an increase in the hazard.

Show the Complete North American Avalanche Danger Scale

North American Public Avalanche Danger Scale

Avalanche danger is determined by the likelihood, size and distribution of avalanches.

Danger Level

Travel Advice

Likelihood of Avalanches

Avalanche Size and Distribution

5 Extreme

Avoid all avalanche terrain.

Natural and human- triggered avalanches certain.

Large to very large avalanches in many areas.

4 High

Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.

Natural avalanches likely; human- triggered avalanches very likely.

Large avalanches in many areas; or very large avalanches in specific areas.

With the 1-2 combo of new snow and strong winds in the forecast, we have prime conditions for avalanche activity. It's always good to remember simple rules about snow. The first one being, 'snow does not like rapid change.' With these stronger winds, look for loading on slopes to occur lower than normally seen. Notice that our avalanche problems have changed, literally, overnight. While wind slabs are the primary problem today, we need to remember what the snow surface looked like before this new loading began. Above treeline we were seeing a weak snow surface underlain by everything from stiff old windslab to several feet of faceted snow. This tired old snow we've been looking at is quickly becoming the new weak layer & bed surface. Wind slabs will be most prominent above treeline. It will be critical to pay attention to the terrain you are under today and know if you are in a runout zone. Conservative travel practices will be critical as avalanches starting in the upper elevations have the potential to run into lower elevation runout zones. Keep in mind that visibility will limit your ability to know where you are in relation to these areas.

Avalanche Problem 2

While it's exciting to finally see the white stuff falling again, it is important to remember what this new snow is falling on; very weak faceted snow. The second simple rule for snow for today: 'strong snow over weak snow equals a problem.' The weight of this new load alone should be enough to tip the balance, especially by the afternoon. By adding in a person or snowmachine to the mix avalanches will be much more likely to occur. Given what the base of the snowpack looks like, loose and rotten, all areas with new snow should be viewed as guilty until proven innocent. If you are seeing avalanches, shooting cracks or getting collapsing/whoompfing, it is time to back off of any slopes steep enough to slide. Expect these signs to become more prevalent throughout the day.

TIMING...BLIZZARD CONDITIONS WILL BE DEVELOPING MONDAY MORNING AS SNOW INTENSIFIES AND WINDS INCREASE. HEAVY SNOW AND BLOWING SNOW WILL CONTINUE INTO LATE TUESDAY MORNING BEFORE SNOW BEGINS TO DIMINISH IN INTENSITY.

We've seen temps climb since Saturday and snowfall has begun overnight. 4-6 inches of snow has fallen so far in the forecast area. Temperatures are currently in the low 20's and ridgetop winds are averaging 20 mph out of the East.

Expect snowfall and winds to intensify throughout the day today. We should expect to see a foot of new snow with ridgetop winds out of the East gusting to 60 mph. Expect to see snowfall amounts much higher in windloaded starting zones.

The long term outlook calls for more snow and wind to impact our area through the week. Continue to check the advisory throughout this holiday week as this active weather pattern will contribute to potentially heightened avalanche conditions.

This is a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area (this advisory does not apply to highways, railroads, or operating ski areas).

Kevin will issue the next advisory Tuesday morning December 25th.

This is a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area (this advisory does not apply to highways, railroads, or operating ski areas).

Riding status is not associated with avalanche danger. An area will be open to motorized use in accordance to the Forest Management Plan when snow coverage is adequate to protect underlying vegetation. Backcountry hazards including avalanche hazard are always present regardless of the open status of motorized use areas.

(Updated: Mar 20, 2019 )

AREA

STATUS

WEATHER AND RIDING CONDITIONS

Glacier District

Johnson Pass:

Open

Placer River:

Closed

Closed as of 3.20.19 due to lack of snow.

Skookum Drainage:

Closed

Placer access closed as of 3.20.19 due to lack of snow.

Turnagain Pass:

Open

Twentymile:

Closed

Closed as of 3.20.19 due to lack of snow.

Seward District

Carter Lake:

Open

Lost Lake Trail:

Open

Please stay on trail to avoid resource damage through forested areas.

Primrose Trail:

Open

Please stay on trail to avoid resource damage through forested areas.

Resurrection Pass Trail:

Closed

Closed for the 2018/19 season. Next season will be open to motorized use.

Chance of Avalanches

This graphic depicts how likely you are to trigger avalanches or encounter natural avalanches while traveling on avalanche prone slopes. Unlikely means that few avalanches could be triggered in avalanche terrain and natural avalanches are not expected. The chance of triggering or observing avalanches increases as we move up the scale. Certain means that humans will be able to trigger avalanches on many slopes, and natural avalanches should be expected.

Size of Avalanches

This graphic depicts the potential size and destructive force of expected avalanches. Small avalanches are not large enough to bury humans and are relatively harmless unless they carry people over cliffs or through trees or rocks. Moving up the scale, avalanches become large enough to bury, injure, or kill people, large enough to bury or destroy vehicles and break a few trees, and large enough to destroy railway cars, buildings, or a substantial amount of forest. Historic avalanches are massive events capable of destroying villages and gouging or altering the landscape.

Chance of Avalanches

This graphic depicts how likely you are to trigger avalanches or encounter natural avalanches while traveling on avalanche prone slopes. Unlikely means that few avalanches could be triggered in avalanche terrain and natural avalanches are not expected. The chance of triggering or observing avalanches increases as we move up the scale. Certain means that humans will be able to trigger avalanches on many slopes, and natural avalanches should be expected.

Size of Avalanches

This graphic depicts the potential size and destructive force of expected avalanches. Small avalanches are not large enough to bury humans and are relatively harmless unless they carry people over cliffs or through trees or rocks. Moving up the scale, avalanches become large enough to bury, injure, or kill people, large enough to bury or destroy vehicles and break a few trees, and large enough to destroy railway cars, buildings, or a substantial amount of forest. Historic avalanches are massive events capable of destroying villages and gouging or altering the landscape.

The information in this advisory is from the U.S. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur.
This advisory provided by the Chugach National Forest, in partnership with Friends of the Chugach National Forest Avalanche Information Center.